Problem: Simplify the following expression: $n = \dfrac{r + 5}{3r - 8} \div \dfrac{1}{5}$
Answer: Dividing by a number is the same as multiplying by its inverse. $n = \dfrac{r + 5}{3r - 8} \times \dfrac{5}{1}$ When multiplying fractions, we multiply the numerators and the denominators. $n = \dfrac{(r + 5) \times 5} {(3r - 8) \times 1}$ $n = \dfrac{5r + 25}{3r - 8}$